Train dispatching system for railroads



April 5, 1932.

05.! 1 c FIG. 1. A 3+ F. B HITCHCOCK TRAIN DxsPA'irmuNG SYSTEM FORRAILROADS Filed April 29. 1929 2/6, I VENT R 4 Sheets-Sheet 1 April 5,1932. F. B. HITCHCOCK TRAIN DISPATCHING SYSTEM FOR RAIL-ROADS FiledApril 29, 1929 4 Sheets-Sheet .mudi

BY 1/ MW ATTOR'NEY April 5, 1932. F. B. HITCHCOCK TRAIN DISPATCHINGSYSTEM FOR RAILRQADS Filed April 29, 1929 4 Sheets-Sheet 3 m m. Mm T N 40 w n m Mm 3m U NI n I I u n2 an 2 1---- a u a l r F+Q hN M v m aw a 1%2m .m.o I fi fi Lg mg 3 w. r u n MN NNIIMAQIAI! 0. 1 #8 w a 3 W Nam mmP4| m V and an moo HA w H 0mm 6 l 1 2 3; 5m

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April 1932- F. B HITCHCOCK TRAIN DISPATCHING SYSTEM FOR RAILRQADS 4Sheets-Sheet 4 Filed April 29. 1929 Patented Apr. 5, 1932 UNITED STATESPATENT @FFKIE FOREST B. HITCI-ICOGK, OF ROCHESTER, NEW YORK, ASSIGNOR TOGENERAL RAILWAY SIGNAL COIVIPANY, OF ROCHESTER, NEW YORK TRAINDISPATCHING SYSTEM FOR RAILROADS Application filed April 29,

This invention relates to a train dispatching system of the type inwhich the dispatcher can control distant switch machines, in whichtrains are dispatched by wayside signal indications, and in which thecontrol over the signals and switch machines, and the indication of theprogress of trains, is transmitted over a comparatively few line wires,by apparatus of the synchronous selector 1:) type.

F or the movements of trains to be properly controlled by a dispatcher,the switch machines and signals which serve as a means to direct thetrains, must be under immediate control of the dispatcher. The timelimit of this control must necessarily be reduced to a minimum value,when the dispatcher finds it advantageous to negotiate non-stop trainmeets, which is one of the advantages of a dispatching system applied interritory where excessive grades are prevalent. To facilitate in thisrapid dispatching of train movements, it is necessary that the OSindications be received by the dispatcher as soon as possible.

In a synchronous selector type dispatching system, a certain eriod oftime is required for the setting up of each message channel insuccession. As the number of control impulses actually transmittedduring a particular cycle of operation are few in comparison with thetotal number of message channels available for the transmission ofcontrol impulses, it is considered advisable. as set forth in the patentto f). H. Diclze and Neil D. Preston No, 1,794,591, dated March 3, 1931,to have the message channels which are to be used for control impulses,set up only when there is a control impulse to be transmitted. In such asystem, as set forth in the above mentioned application, where thecontrol of the dispatcher over a way-station is transferred from onewaystation to another waystation successively, and where the OS indication impulses are picked up the transfor is made from station tostation, with the operation of the message channelselect-ing relays usedonly for control impulses, conlerahle time is saved, so that the OSindications from various way-stations are transthat is transferring thecontrol of the dispatcher from one way-station to the next in rapidsuccession, has the advantage that the message channels of eachway-station are isolated except at such time when they are to be used,which reduces the hazard of false indications, or continuous shortscaused by the inoperation of some mechanism at a waystation, to affectall the message channels of the system. This type of system also has theadvantage, that further additions may be made to the system by simplyadding more stations without altering the existing stations. Ifhowever,the central otlice, or dispatchers oflice, has rotary mechanismsto govern the control over the way-stations, then it is necessary thatthe rotary mechanisms be built with spare spaces or replaced by newmechanisms in case of further extension of the system.

To alleviate the necessity for altering the existing apparatus in thedispatchers oliice when a synchronous type selector system is extended,it is easily seen that, when nonmechanical rotation is utilized, whichmay be accomplished by successively operated relays, that furtheradditions may be made by merely adding the necessary relays.

In the case of a railroad which has a synchronous selector typedispatching system installed, using the transfer from station to stationmethod of control, over a long distance, it would be advisable, if itwere pos sible, to be able to operate the system up to a break in linewires, or up to a point where a short or other defects, were causinginoperation of the dispatching system. In other words, if a dispatcherhas trouble with his system, and can ascertain at what point thistrouble is occurring, and can by slight ma nipulation of a switch orother means, acquire use of that part of the system up to that point atwhich the disturbance is occurring, then he would still have a chance tooperate trains on part of his system automatically while a maintainer issent to locate and remedy the trouble.

It is also readily understood, that in such a system where a greatnumber of relays are used, that it is desirable to have the system atrest when no indications are waiting to be transmitted, to eliminate asmany relay operations as possible.

In view of the above considerations and others, it is proposed to use inaccordance with the present invention a self stepping synchronousselector system, which is entirely operable through the use of properlydesigned relay mechanisms, control levers and indicators, and having theOS and control impulses transmitted over a certain required number ofmessage channels successively set up, so that the dispatcher from a.central office may have control over the switch machines, signals,de-rails and the like, and receive OS indications, within the territoryover which he has control. In accordance with the present invention, itis proposed to transmit a plurality of positive impulses to eii'ect thetransfer of the dispatchers control over the way-stations from oneway-station to the next way-station, with the control given to eachstation in succession with successive .positive impulses, which givecontrol over a way-station during the length of time that each positiveimpulse is maintained, and when such control over each way-station hasbeen successively set up, then the original starting position shall beobtained by a negative impulse. Also, during such time that the systemis transferring from one station to the next, the OS indications shallbe picked up, as each station is successively under control, and themessage channels used for control impulses shall be set up only at suchtime when a control lever has been moved to a new position, with suchmessage channels established by the simultaneous operation of a group ofrelays at the dispatchefls ofiice and a group of relaysat theway-station to which the control impulse is to be transmitted, whichgroups of relays shall operate to set up the required message channel.The operation of these groups of relays which set up the messagechannels for control impulses shal l'be effected by the transmission ofa plurality of alternate positive and negative impulses over-thestepping circuit, including the stepping wire and the common returnwire, of which each impulse will energize and move one of the abovementioned relays in the dispatchers office and one in the way-stationunder control, during which period of time that exists between themovement of two successive relays, a control impulse from thedispatchers ofiice may be transmitted over the message channels therebyset up. The present invention, also includes means whereby the systemshall be normally at rest, and may be initiated, either by the movementof a control lever at the dispatchers ofiice to a new position, or bythe changing of the position of a track relay at any way-station.

Other objects, purposes and characteristic features of the presentinvention will in part be obvious from the accompanying drawings and inpart pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to theaccompanying drawings, in which Fig. 1A and Fig. 113, when placed end toend, illustrate conventionally the equipment in the dispatchers oificefor automatically shifting the control of the dispatcher from oneway-station to the next in rapid succession, and automatically stoppingit at a waystation to which a control impulse is to be transmitted, andautomatically and sequentially operating the channel selecting relays atthat station to set up the required message channel;

Fig. 1C illustrates conventionally the equipment of one way-station withthe apparatus shown connected conventionally to control relays whichhave control over the switch machine and signals located at the west endof apassing siding;

Fig. 1D represents the equipment at a Waystation similar to theway-station shown in Fig. 10 but connected so that control may beestablished over the east end of a passing siding; also, showing theequipment at a Waystation for transmiting an OS indication at apermissive signal of an absolute-permissiveblock signal system.

Description of apparatus Although in practice, the dispatcher controlsthe switch machines and wayside signals of a large portion of arailway'system, possibly including many passing sidings, divergingroutes, draw bridges, railway crossings, and the like, the presentinvention has for convenience been shown as applied to the apparatuslocated at the east and west ends of the passing siding PS and at apermissive block signal SW7 (see Figs. 1C and 1D). The passing siding PSconnects to a main track, having sections TK TK TK and TK of a singletrack railway system signalled with absolute-permissive-blocksignalling,except at track sections, such as sections TK and TK which are under thecontrol of the dispatcher. The track sections TK and TK contain trackswitches TS and TS respectively, which have associated therewith theusual detector track circuits. Track section TK including a foulingtrack section F55 is enclosed by insulated joints 1 and 2. Likewise, thetrack section TK including a fouling track section FS is enclosed byinsulated joints 3 and 4:. The track section TK belongs to the regularabsolute-permissive-block signal system and is separated from the restof the track by insulated joints 4 and 5. These track sections TK TK andTK have track batteries 6, 7 and 8 respectively, associated therewith,to supply energy to 1gheir respective track relays TR TR and T Thestarting signals for the main track and siding at the west end of thepassing siding PS have been designated SWV and SW respectively, and atthe east end of the passing siding PS have been designated SE and SErespectively. At the west end of the passing siding PS is the main linesignal and the take siding signal, SE and SE respectively and at theeast end of the passing siding PS is the main line si nal and the takesiding signal SW and SW respectively. The permissive signal SW islocated at the east end of the track section TK In the dispatcherso'liice, is preferably located a miniature track layout (see Fig. 1A)corresponding in every detail to thesystem over which the dispatcher hascontrol, and in the particular arrangement shown includes the passingsiding ps and the main line track sections 2716 tlc and t7c Thisminiature track layout has indicating lamps P, P, 1 associatedtherewith, which if illuminated, indicate the occupancy of thecorresponding track circuits, namely, the track circuits of tracksections TK TK and TK respectively. The track switch TS at the west endof the passing siding PS is preferably controlled by the switch machinerelay SMR which relay is in turn controlled by the lever SML through themedium of the self step ping synchronous system hereinafter described.Similarly, the signals SE SE SW and SW are controlledgby the signalrelay SR and the direction relay DB through the medium of thesynchronous selector system in accordance with the position of the leverSL located in the dispatchers ofiice. Also, the track switch TS and thesignals SE SE SW and SW are likewise controlled in accordance with theirrespective control lever SML and SL in the dispatchers ofiice. Themanner, in which such relays, as relays SMR DB SR may control theirrespective functions, is fully set forth in pending application by S. N.Night, Ser. No. 321,185, filed Nov. 22, 1928.

The dispatchers office contains a number of relays, so grouped andinter-related in their respective functions, as to accomplish theoperation of the system automatically. Thesevarious functions of therelays involved, serve to give them distinctive group names anddistinguishing reference characters.

The group of relays 1 2 and 3 are the control impulse message channelselecting relays for the first way-station, in which the order of thenumber gives the order of se quent-ial operation for that station, andthe order of the exponent gives the order of the station. Similarly, thegroup of relays 1 2 and 3 are the controlimpulse message channelselecting relays for the second waystation, with the referencecharacters having a like meaning. The energizing circuits for thesegroups of message channel selecting relays are repeated by the linerelay L and the particular group to be operated is selected by thestation selecting relays ST ST and ST in which the exponents representthe order of the way-station to which they are assigned. The initiatinrelay IN and the control relay CR serve to initiate and control theduration of the sequential operation of the system respectively, intransferring the control of the dispatcher from one way-station to theneXt way-station, having associated therewith the cycle checking relays(HQ and (3K which control the relays 1N and GR'in such a manner, thatthe system shall complete two cycles of non-mechanical rotation, aftereach time that the initiatingrelay IN" has been energized. The transferimpulse generating group is composed of an operating relay OPR, thecontrol checking relays CC, CC and CS the impulse polarity relays N andP, and the re-set relay RE. Also, the stepping impulse generating groupis composed of the master relay MR, and two time spacing repeater relaysS and S. This stepping impulse generating group has associated therewiththe starting relay ST and the stopping relay STP. The control of thestepping impulse generating group and associated relays is determined bythe group selecting relays G and G which are in turn controlled by themovement of a control lever effected by the dispatcher. There are alsotwo voltage regulating relays VH and VH which serve to shunt outportions of the voltage regulating resistance such as VRR and VRPJ asthe dispatchers control is transferred from one way-station to the nextwaystation. This is necessary, inasmuch as, each time the-transfer ofcontrol is accomplished, 1

an added transfer relay is placed in series with the line as well as anadded amount of line wire. A transfer relay TRAN", serves to repeat inthe dispatchers ofiice the conditions imposed upon the transfer controlwire. An indicator lamp I is included at the dispatchers office, toindicate such time that the transfer relay ceases to function, due to anopening in the transfer control wire. An automatic cut-out A is insertedin the transfor control wire circuit, which serves to open the saidcircuit, in case an excessive current flows through said cut-out A".This cut-out A also has associated therewith an ampere meter M andfurnishes a means whereby the operator may ascertain approximately wherethere is a short upon the transfer control wire. Thus, in order that thedispatcher may utilize the knowledge that he has certain trouble uponthe transfer wire, a transfer trouble switch TTS is furnished, whichprovides a means whereby the operator may regulate the transfer controlcircuits in such a manner that the system may be operated automaticallyto the certain point in the system at which the known trouble occurs.

For purposes of simplification, the points in the circuits which areconnected to the common Wire, have arrows with reference char *acters C.

Suitable power supply, for the transfer control impulses, is provided bythe batteries BT and BT connected together to give negative and positivepotentials respectively, in respect to the central point of thebatteries connected to the common wire. Also the stepping impulse powersupply, is furnished by the batteries BT and BT and are connected togive positive and negative potentials respectively, in respect to thecentral point of the batteries connected to said comm'on wire. Variousother points in the circuits which require positive and negativepotentials in respect to said common wire, are indicated as (13+) and(B) respectively, which in the dispatchers office, may be battery BT orBT' or other separate sources. Likewise, the indicated sources for thewaystations, are separate batteries at each waystation, which givepositive or negative potentials in respect to said common wire, and aremaintained charged in any suitable manner such as some trickle chargemethod.

The dispatchers ofiice is connected to the way-stations (see Figs. 16and ID) by four line wires, consisting of a common wire 200, a transferwire 201, a stepping wire 202, and av message wire 203. The way-stationshown in Fig. 1C, as connected to'the west end of a passing siding PS,is identical to the way station shown in Fig. 1D as connected to theeast end of the same passing siding PS. The way-station shown in Fig. IDas located at the permissive block signal SW has transfer as well aseffecting the tequipment identical with the other two waystations shown,but with the control impulse message channel selecting relays omitted.The relays duplicated in the several stations have like referencecharacters with suitable exponents distinguishing the station to whichthey belong. Thus. only the way-station shown in Fig. 1C will be brieflydescribed.

This way-station shown in Fig. 1C has a transfer relay THANK of thepolar neutral type which controls in turn and sequentially the stationselecting relay S and the station shunting relay SS These relayscomposing the transfer group, give control over the message channelselecting rela s A B and C to the next way-station, The energizingcircuit of the message channel selecting relays, is repeated by the linerelay L when the transfer group has selected this particular station. AnOS storing relay USS is provided to hold the OS indication until theinitiating relay 1N has initiated and operated the synchronous selectorsystem up to this waystation, so that the said US indicationcan beregistered at the dispatchers oflice.

It will be stated here, that all polar relays are considered to assume aright hand or positive position, with an application of positivepotential to the left hand terminal of the relay, and to assume a lefthand or negative position, with application of negative potential to theleft hand terminal of the relay. It is also assumed, that the normalposition of all relays are in their present full line position, so thatwhen a relay is spoken of as being in a reverse or abnormal position itshall mean the dotted line position as shown in the accompanyingdrawings.

The relays L L L OPE, and MR are of the biased to neutral type of polarrelay. In other words, their armatures move ac cording to the polarityapplied due to the permanent magnet incorporated, but assume a neutralposition when de-energized. Other polar relays are of the polarpermanent magnet stick type which respond to an energy impulse of acertain polarity by moving its contacts to a position determined by thatpolarity, due to a permanent magnet which is incorporated within therelay. This permanent magnet holds the armature when moved to an extremeposition even though the relay is then (lo-energized.

The neutral relays incorporated within the circuits of the system are ofthe usual type and are shown conventionally with heavy line bases insuch cases where they have a slow releasing period.

Lever SML has connected to it by mechanical means contact 9 which movesto its dotted line position when the lever EMT is moved to its dottedline position. Also the lever SL has connected to it by mechanical meansthe contacts 10 and 11, which move to their right hand dotted linepositions with the movement of the lever SL to a left hand dotted lineposition with corresponding opposite movements with lever SL moved to aright hand position. Similarly the levers SML and SL have associatedtherewith corresponding contacts 12, 13 and 14 respectively.

It is believed that the system will. be better understood with furtherdescription being set forth from the stand point of operation.

Operation In a train dispatching system of the syn chronous countingrelay type, in which successive way stations are selected one at a time,there are four distinctive characteristic conditions which the stationselecting apparatus at each way station must be capable of producing,namely;

( 1) A normal at rest condition, during which time all the way stationsshall be at rest, and during which time a circuit may be set up at anyway station for initiating the system, with this at rest condition beingimmediately cancelled as soon as the system becomes initiated;

(2) A before selection condition, which is set up immediately after theatrest period, which before selection condition determines that all theway stations shall be idle except the first way station which is tobeunder control;

(3) A selected condition, which is maintained at the way station underoperating control and which is characteristic only of such station thatis under operating control;

(4;) An after selectiolwcondition which is maintained by all waystations that have been under operating control, until the normal atrest condition is repeated, with such an after selection condition whichallows the remaining way stations to be successively placed undercontrol, maintaining these way stations which have been under control inan idle condition.

It will be noted, that the condition which is used for the at restperiod and for initiation is the same condition which resets the waystations to a normal at rest condition. These various conditions must beduplicated at the dispatchers oliice in such a manner that the apparatusat the dispatchers office may control the conditions automatically andcause the system to work in a certain predetermined sequence ofoperation.

It is believed that the various conditions set up by the system and thesequential operations and functions of the mechanisms included will bebest understood by a detailed description of several cycles ofoperation.

Normal at rest comlz'tiom With the system at rest, the initiating relay1N and control relay OR are de-energized, completing' a circuit for there-set relay RE, which, when energized, places negative potential uponthe transfer wire'201, energizing the transfer relays TRAN", TRAN TRANand TRAN so that their polar contacts are in a negative position andtheir neutral, contacts are in an energized position. With the transferrelays thus energized, the station shunting relays SS SS and SS are alsoenergizech The circuit for relay RE is traced as follows :from positiveterminal of indicated source having suitable potential, through relayRE, wires 15 and 16, back contact 17 of relay OR, to the common wire200.

The circuit for placing negative potential upon the transfer wire 201 istraced as follows :negative potential from the battery BT through wire18, front contact 19, wire 20, transfer wire 201, transfer relay TRAN",transfer wire 201 to the first way station, transfer relay TRAN throughthe transfer wire 201 to the second way station, transfer relay TRANthrough the transfer wire 201 to the third way station, transfer relayTRAN to the common wire 200.

At the first way station, relay SS is energized through the circuittraced as follows from positive terminal of indicated source havingsuitable potential, through the relay SS wire 21, wire 22, front contact23 of relay TRAN wire 24, negative contact 25 of relay TRANQ to thecommon wire 200. Through similar symmetrical circuits, therelays SS andare held in energized positions.

Transmission of 0S miicati0ns.Let us assume, that a train travelling ina west bound direction enters the track section TK at thepermissive-block-signal SW The OS indication, representing the presenceof this train, is stored in the OS storing relay OSS by accomplishingits energization as a result of the shunting of track relay TR Theenergization of the relay OSS momentarily completes a circuit forenergizing the initiating relay 1N which remains energized due to astick circuit, until the OS indication in the relay OSS has beentransmitted to the dispatchers ofiice. This is because the initiatingrelay 1N when energized, also closes a stick circuit for the relay OSSThis combination of interconnection provides a means whereby the OSindication is insured of being transmitted to the dispatchers of fice,whether or not, the train leaves this particular track section beforeits OS indication has been transmitted, which would occur providing thetrack section TK is exceptionally short and the train is travelling at ahigh rate of speed.

More specifically considering the operation, the occupancy of tracksection TK, shunts the track relay TB so that its contact 26 assumes aole-energized position, which sets up an energizing circuit for the OSstoring relay OSS through a circuit traced as follows :from negativeterminal of indicated source having suitable potential,

through relay OSS wire 27, back contact 26 of relay TR- to the commonwire 200. During the energization of relay OSS a momentary energizingcircuit for the relay IN is completed, being traced as follows 7 frompositive terminal of indicated source having suitable potential, throughrelay 1N Wires 28 and 29, make before break contact 30, to the commonwire 200. As soon as, the relay IN is energized, a stick circuit iscompleted for both the relays 1N and OSS This stick circuit for therelay 1N is traced as follows :from positive terminal of indicatedsource having suitable potential, through relay OSS wire 94, frontcontact 46, wire 29, front contact 96, wires 169 and 31, front contact32 of relay SS to the common wire 200.

The initiating relay IN and the control follows relayOR, in thedispatchers oifice, are now energized through a circuit completed by theenergization of the relay 1N in the third way station, which circuit isincluded at each way station having identical and symmetricalconnections, so that the system may be initiated from each and everyway-station where OS indications occur. This initiating circuitforthevthirdw'ay station is traced as i from positive terminal of indicatedsource having suitable potential, through upper winding of relay OR,wire 33, relay 1N wires 34, 35 and'36, back contact 37 of relay 8T wire38, back contact. 39 of relay ST wire 40, back contact 41 of relay 8T tothe message wire 203 which is connected to each way station, from themessage wire 208 at the third Way station through wire 42, front contact43. and negative contact 44 of relay TRAN wire45, front contact 95, tothe common wire 200.

With the contacts ofrelays IN and OR in the dispatchers office, inenergized positions, circuits are completed whereby the relays N and]?operate to alternately place positive and negative impulses upon theoperating relay OPR, whichin turn sequentially operates thestationselecting relays STl, ST and ST The energizingcircuits of the relay OPRare-carried through the-relay CO in such a manner that the contact 72 ofrelay OO assumes a position which is in accordance withthe'energizationof. either relay N or relay P, and in accordance with the polarity ofthe potential applied to the relay OPE.

VVith-the-rclay CR energized, the energizingicircuit for the re-setrelay RE is broken at contact 17 of relay OR. At thesame time, the frontcontact 47 ofrelay IN closes a stick circuit for relay IN", being tracedas follows :--from positive terminal of indicated source having,suitable potential, through upper Winding of relay CR, wire 33, relay,TN", wires 34' and 35, front contact 47,

"- wire 48, back contact 49, wire 209, front contact225 of relay TN tothe common wire 200. A'lso,a stick circuit is completed for relayORib-eing traced as follows:from positive terminal of indicated sourcehaving suitable potential, through the lower winding of relay OR," frontcontact 50, Wire 51, back contact 52, to the common wire 200. Theenergization of relay OR closes a circuit for energizing the relayPbeing traced as fol.- lows:from positive terminal of indicated sourcehaving suitable potential, through front contact 53 of relay OR, wires54 and 55, relay P, wires 56, 284 and 285, front con tact 57, wire-58,back contact 59 of relay 81, wire 60', back contact 61 of relay ST wire62, back contact 63 of relay. ST to the common wire 200; Theenergization of relay P closesits stick circuit, being traced as follows:from positive terminal of indicated source having su1table potent1al,front "contee tact 53 of relay OR, wires 54 and 55, relay P, wires 56,284 and 286, front contact 64 of relay l ire 65, back contact 66 ofrelay N, to the common wire 200. The energization of relay P placespositive potential on the relay OPE through a circuit traced asfollows:from the positive terminal of indicated source having suitablepotential, through upper winding of relay wire 67, back contact 68, wire69, front contact 70, wire 71, through relay OPE, to the common wire200. The current that flows in this circuit just traced energizes thecontact 72 of relay CO to a positive position, and the contacts 73 and74 of relay OPR to a positive position.

The de-energization of the slow releasing relay RE opens the energizingcircu of the transfer relays 'lRAN TRAN Than 2 and TRAN at the frontcontact 19 of relay RE, as the slow releasing period consumes enoughtime to permit the relays SS SS and SS to become fully de-ener' izedbefore a positive potential is placed upon the transfer wire by thecontacts of relay OPE being in a positive position. This de-energizationof the station shunting relays SS SS and accomplished thesectionalization of the transfer line wire 201 by shunting the transferwire at each station on the side of the trans fer relay away from thedispatchers ollice, to the common wire 200. This is more specificallyshown by referring to the first way station, shown in Fig. 10, where thetransfer wire 201 on the right hand side of transfer relay TRAN isconnected to the common wire 200 by means of the wire 291 and thebackcontact 292 of relay SS It will be noted that each of the other w ystations have similar circuits for shunting the succeeding transferrelays out of the circuit.

The de-energization of relays TRAN and SS reroute the stick circuit ofthe relay OSS through aback contact of relay TRAN his stick circuit ofrelay OSS is traced as follows:from positive terminal of indicatedsource having suitable potential, through relay OSS wire 94, frontcontact 46 of relay OSS wire 29, front contact 96 of relay 1N wires 169and 293, back contact 170 of relay TRAN Wire 171, negative contact 172of relay TRAN to the common wire 200.

As soon as, the contacts of relay RE assume a fully (ls-energizedposition, positive impulse being placed on the relay OPE, a circuit iscompleted which places positive potential upon the tra sfcr wire 201.Positive potential upon the transfer wire 201, energizes the relays THANand TRAN in such a manner that the polar contacts are energized to apositive position before their neutral contacts assume an energizedposition, which is the natural characteristic of polar neutral relays.With the polar contacts of relay TRAN in a positive position the relaySS cannot be picked up, hence the transfer relays TRAN and TRA\ areshunted out of the transfer line circuit. Also, with the polar contactsof relay TRAN in positive position, the relays S is energized as soon asthe natural contacts of said relay TRAN have assumed an energizedposition. The energization of relay S permits the energization of relaySS When the relay TRAN is de-energized. Such a' combination results,that once the transfer relay TRAN has been energized With a positiveimpuse and again de-energized, then the relays S and SS are energizedand held in energized positions through their own stick circuits, Whichare not broken until the transfer relay 'lRAN has been again energizedWith a negative impulse. The operation and function of the transfergroup at other Way stations is identical With the operation and functionof the transfer group at the first Way station. The circuit for placingthe positive potential upon the transferred Wire 201 is traced asfollows :from the positive terminal of battery BT through theresistances VRR and VRR", through the automatic cut-out A", back contact75, Wire 76, positive contact 73 of relay ()PR, to the transfer Wire 201through transfer relay TRAN", transfer Wire to the first Way station,through transfer relay TRAN to the common Wire 200. This positiveimpulse energizes the transfer relays TRAN and TRAN so that their polarcontacts assume a positive position and their neutral contacts assume anenergized position. With the relay TRAN thus energized a circuit iscompleted for energizing the station selecting relay 8T being traced asfollowsz-from the positive terminal of indicated source having suitablepotential, positive contact 77 and front contact 78 of relay TRAN", Wire79, positive contact 74, wire 80, back contact 153, Wire 81, relay 8TWire 82, back contact 83, Wires 8% and 287 back contact 85, Wires 289,215 and 86, positive contact 87 of relay TRAN", to the common Wire 200.Thus, the station selecting relay ST is energized completing a stickcircuit, Which is traced as follows :from positive terminal of indicatedsource having suitable potential, throughfront contact 88 of relay 8Trelay ST Wire 82, through a circuit heretofore traced to the common Wire200.

The cycle checking relay CK is energized at the same time that'thestation selecting relay ST is energized, due to the fact, that bothenergizing circuits are carried through the positive contact 87 of relayTRAN". This circuit which energizes the relay CK also holds, it in anenergized position until the first cycle has been, completed, as Well asfurnishing the energy for the stick circuit of the relay IN". Thisenergizing circuit of relay CK is traced as follows :from positiveterminal of indicated source having suitable potential, through relay(1K Wire 163, front contact 16%, wires 167, 165, 215 and 86, positivecontact 87 of relay TRAN to the common Wire 200. Through the contacts ofrelay CK in an energized position, the stick circuit for the relay IN istraced as follows :from the positive terminal of indicated source havingsuitable potential, through upper Winding of relay CR, Wire 33, relayTN", Wires .341 and 35, front contact 47 of relay IN", Wire 48, frontcontact 49 of relay CK Wire 163, front contact 164 of relay IN, Wires167, 165, 215 and 86, positive contact 87 of relay TRAN", to the commonWire 200.

At the same time, that the station selecting relay ST in the dispatchersoffice is energized, the station relay S at the first Way station isenergized due to the energization of the transfer relay TRAN The relay Sis energized through a circuit traced as follows z-from positiveterminal of indicated source having suitable potential, through frontcontact 89 of relay TRAN Wire 90, relay S Wires 91 and 290, positivecontact 25 of relay TRAN to the common Wire 200. Immediately, uponenergization of relay S its stick circuit is closed, being traced asfollows :from positive terminal of indicated source having suitablepotential, through front contact 92 of relay S Wire 93, relay S Wires 91and 290, positive contact 25 of relay TRAN to the common Wire 200.

At tl e time that the relays ST and S are energized a message circuit iscompleted which allows the OS indication at the first Way station, shownin Fig. 1G, to be transmitted to the dispatchers oflice. This messagechannel is traced as follows :from negative termina-l of indicatedsource having suitable potential, through hack contact 156 of relay OSSWire 97, back contact 98 of relay A Wire 99, back contact 100 of relay BWire 101, back contact 102 of relay C Wire 103, back contact 104 ofrelay SS Wire 105, front contact 106 of relay S Wire 107, positivecontact 108 and front contact 109 of relay TRANE Wire 280, to themessage Wire 203, to

the dispatchers ofiice, hack contact 41 of relay ST wire 4,-0, backcontact 39, Wire 38, front contact 37, Wire 110, back contact 111 ofrelay 3 Wire 112, back contact 113, Wire 114, back contact 115, Wire116, relay CS to the common Wire 200. The polar contact of relay CS isthus energized to a negative position, allowing the indicator lamp I toremain unilluminated, indicating to the dispatcher that there is notrain occupying the track section TK As soon as, the relay ST becomesenergized, a circuit is completed, energizing the relay N which opensthe stick circuit of relay P, closes its own stick circuit, and closes acircuit Which will place negative potential upon the relay OPR as soonas the sloW releasing relay P reaches a de-energized position.

This energizing circuit for the relay N is traced as follows :from thepositive terminal of indicated source having suitable potential, throughfront contact 53 of relay CR, wires 54 and 175, relay N, wires 176, 177and 178, back contact 179, wire 180, and 181, front contact 182 of relayST wire 60, back contact 61, wire 62 and 185, back contact 63 to thecommon. wire 200. The stick circuit for the relay N is traced as follows:from positive terminal of indicated source having suitablepotential,front contact 53 of relay CR, wires 54:,and. 175, relay N,wires 17 6 and 177, front contact 186 of relay N, wire 187, frontcontact 188 of relay P, to the common wire 200. Thus, there is a periodof time between the end of the first positive impulse placed upon thetransfer wire 201 and the beginning of the second positive impulseallowing sufficient time for the relay TRAN to become deenergized thuspicking up the relay SS The cnergization of relay SS allows the secondway station to be selected as soon as the succeedingpositive impulse isapplied.

, The relay SS is energized through a circuit traced as follows :frompositive termi nal of indicated source having suitable potential,through relay SS wires 21 and 22, front contact 117, wire 118, backcontact 119, to the common wire 200.. Thus the relay SS is energizedwhich completes a stick circuit traced as follows :from positiveterminal of indicated source having suitable potential, through relay SSwire 21, front contact of relay SS wire 121, front contact 122,

wire 131, positive contact of relay TRAN to the common wire 200.

With the relay N energized and the relay de-energized, negativepotential is placed upon the relay OPR through a circuit traced follows::from negative terminal of indicated source having suitable potential,through lower winding 0t relay CC, wire 123, back contact 124 of relayP, wire 125, front contact 126 of relay N, wire 71, relay (JFK, to thecommon wire 200. Thus, the contacts 73 and 74 of relay OPE are energizedto a negative position, thus, placing a positive impulse upon thetransfer wire 201, and also a positive in'ipulse on wire 127 energizingthe relay 3T through a circuit raced as follows from positive terminalof indicated source having suitable potential, through positive contact77 and front contact 78 of relay TRAN", wire 79, negative contact 74,wire 127, front contact 128 of relay 81, wire 129, relay ST wires 288and 287, back contact 85, wires 289, 215 and 86, positive contact 87 ofrelay TRAN to the common wire 200.

With the contact 73 of relay OPR in a negative position, a positiveimpulse is placed on the transfer wire 201 energizing the rele ys TRANand TRAN? Vith relay TRAN energized, the relay S is energized through acircuit identical, with the energizing circuit of relay S heretoforetraced. It is likewise, in. a similar manner held in an energizedposition through a stick circuit.

\Vith the relays ST in energized positions, a message channel is set upwhich allows the ()Sindication of the econd way station to betransmitted to the dispatchers oiiice. This message channel is traced asfollows:-from negative terminal of indicated source having a suitablepotential, through back contact 132 of relay OSS wire 133, back contact134 of relay A wire 135, back contact 136 of relay B wire 137, backcontact 138 of relay wire 139, back contact 1400f relay SS wire 1&1,front contact 142 of relay S wire 1&3, positive contact 1 1 1, and frontcontact 145 of relay TRAN wire to the message wire 203, to thedispatchers ofiice, back contact ll of relay 8T wire l0, front contact39, wire 1 13, back contact 14.7, wire 148, back contact 149, wire 150,back contact 151, wire 152, relay CS to the common w se 208. Thus therelay G3 has its polar contact energized. to a negative position, le.ving the indicated lamp I unilluminated which indicates to thedispatcher that the track section T1 is unoccupied.

it. soon as the relay 5T becomes energized circuit is completed,energizing the relay which opens the stick circuit of relay N, (fiOSCSits own stick circuit, and closes a ciruit which will place positivepotential on the re ay OPE as soon as the slow releasing relay N reachesa Clo-energized position.

The energizing circuit for the relay P is traced as follows :frompositive terminal of indicated source having suitable potential, throughfront contact 53 of relay CR, wires 51 and 55, relay P, wires 56, 189and 190, baclz contact 191 of relay G wires 193 and 19 front contact 195of relay ST wire 185, back contact 63 of relay S1, to the common wire200.

During the time that there is no potential on the relay OPE there is nopotential on the us or wire thus allowing the relays TRAN and THEN, toassume a ale-energized posi on. ll ith relay 'llRAlel in a de-energizedposition, its polar contacts in a positive position, and the relay S inan energized po sition, the relay SS is energized, through a circuitbeing exactly symmetrical with the circuit described for the relay SS ll hcn the positive potential is placed on the relay OPE, its contacts 73and 7 1 assume positive posit-ion and a positive impulse is placed onthe transfer wire 201 and on the wire 80. Thus, the station selectingrelay ST is energized and he transfer relay 'Ql-ZAll at the third waystation is energized. The relay ST is energized through a circuit tracedas follows :from positive terminal of indicated source having suitablepotential, through positive contact 77, and front contact 78 of relayTRAN", wire 79, positive contact 7 4 of relay OPR, wire 80, frontcontact 153, wire 154, relay ST wires 166 and 86,positive contact 87 ofrelay TRAN", to I the common wire 200. The energization of relay 8Tcloses a stick circuit through front contact 155. The energization ofthe relay TRAN energizes the relay S through circuits exactlysymmetrical as traced for relay S As the relays ST and S simultaneouslyassume energized positions, a message channel is compl ted fortransmitting an OS indication from the third way station to thedispatchers ofi'ice.

Inasmuch as, a train is assumed to be in the track section TI the relayTB is deenergized and the relay OSS is energized, thus a positivepotential is placed upon the message channel. The message channel forthe OS of the third station is traced as follows :-from the positiveterminal of indicated source having suitable potential, through frontcontact 156, wire 15?, back contact 158 of relay SS wire 159, frontcontact 160 of relay S wire 161, positive contact 44: and front contact13 of relay TRAN- wire 42, to the message Wire 203 to the dispatchersoflice, front contact 41, wire 162, relay OS to the common wire 200.Thus, the relay US has its polar contact energized to its positiveposition, illuminating the indicator lamp I with suitable potential asis obvious from the accompanying drawings. I-Ience,the presence of thetrain upon the track section TK is transmitted to the dispatchers oiiiceand indicated to the dispatcher by the illumination of indicator lamp IWhen the relay TRAN is energized with a positive impulse the stickcircuits for the relays OSS and IN as heretofore traced, are broken.Thus, during the time that the relay OSS is being de-energized, the OSindication must be transmitted, which requires that the releasing timeof an OS storing relay, and relay OSS in particular, must have a releaseperiod greater than the sum of the pick up periods of the relays TRANand S Also, the relay IN must have a release pe riod less than the sumof the pickup periods of the relays TR AN and S and greater than thedrop away period of the relay TRAN? In other words, when the system isat rest, the relay IN has a stick circuit, (as heretofore traced) whichis closed through front contact 32 of relay SS but when the system isinitiated and begins operation the neutral armature of relay TR AN dropsaway closing the stick circuit of relay 1N through back contact 170 ofrelay TRAN and opening the stick circuit at front contact 32 of relay SSHowever, the relay SS is slightly slow releasing so that, as the stickcircuit for relay SS when the system is at rest is closed through frontcontact 170 of relay THANK and the stick circuit of relay IN is closedthrough the said back contact 170, then the time consumed by the contact170 to change from an energized to a de-energized position is consumedby the release period of relay SS But to insure that the relay IN shallnot drop away in case the release period of SS was not sufficiently longenough, the relay 1N should have a release period greater than therelease period of relay TRAN Now as the control is transferred from oneway station to another way station, the stick circuit for the relay INis opened as soon as the contact 170 of relay 'lltr ili is energized andis not again closed, until the relay S has been energized, the relayTRAN ole-energized and the relay SS energized. Thus if the releaseperiod of relay Ihl is less than the sum of the pick up periods of relayTRAN and S there is sufficient time allowed in the rel-ease period ofrelay TRAN and the pick up period of relay SS to insure that the relayIN is entirely dropped away. Also, as soon as control is transferredfrom this way station, the stick circuit for relay IN is closed at thecontact 32 of relay SS that should the OS-ing conditions change, thecircuits would again be ready to stick relay IN energized.

Although, the relay IN 'is tie-energized, the relay OSS is stillenergized, due to the fact that the track relay TB is stillde-energized. Hence, it is seen that, after the first time that thesystem is initiated, due to the presence of an OS indication, that it isnot again initiated, although that track section is still occupied. Inother Words, so long as a train remains upon the same track sectionthesystem operates through two cycles only. It is to be understood thatthe transfer relay TRAN has the same operating time characteristic asall other transfer relays and that the station selecting relays 8T STand ST have the same operating characteristics as the relays S S and SThus, the slow release periods of the relays N and P allow plenty oftime for the transmission of OS indications, as corresponding stationselecting relays and station relays have been energized before anothercondition is set up, even through the station selecting relaysimmediately close circuits to positively cause the next condition insequence to occur.

With the energization of relay ST a circuit is closed for energizing there-set relay RE. This circuit for energizing said relay RE is traced asfollows:from positive ter minal of indicated source having suitablepotential, through relay RE, Wires 15 and 173, switch TTS in its presentnormal position, wire 174:, front contact 63 of relay ST to the commonwire 200. The energization of the re-set relay RE, places negativepotential upon the transfer controlwire 201, which energizes the polarcontacts of all transfer relays to a negative position and their neutralcontacts to an energized position establishingthe' atrest condition forthe Way stations; only.

The movement of the polar contacts of relay TRAN" to a negative.position opens, the stick circuit for the relays CK IN" and ST whichimmediately drop. The relay P is still in an energized position due tothe fact, that its stick circuit has not been opened, so that, as soonas the re-set relay RE assumes a de-energized position as its energizingcircuit is opened by the de-energ'ization of relay ST", a positiveimpulse will be placed upon thetransfer line 201. Thus, with thecontacts 73 and 74 of the relay OPR in a positive position, positivepotential is placed on the transfer relays TRAN" and TRAN and thestation selecting relay SF. The system then proceeds to operate in asequential manner as heretofore described for the first cycle,successively placing the Way stations under control of the dispatchersoliice.

It will be noted here, that the voltage regulating relays VR and VB areenergized by thexenergization of station selecting relays ST and STrespectively. The relay VR is energized through a circuit traced asfollows :from the positive termlnal of indicated source having suitablep otentlal, through relay VH wire 183, front contact 182 of. relay STwire 60, back contact 61 of relay ST wires 62 and 185, back contact 63of relay ST to common wire 200. The energizing circuit. for the relay VHis traced as follows :from positive terminal of indicated source havingsuitable potential, through relay V11 wire 196, front contact 195 ofrelay ST", wire 185, back contact 63 of relay ST to the common wire 200.

It will. be noted, that the circuit for energizing the transfer relaysTRAN" and TRAN connected in series is carried through the resistancesVRR and VRR". When the relay ST is energized, closing theenergizingcircuit for relay VH the resistance VRR" is shunted out sothat the circuit hen the relay ST? is energized, energizingthe relay VRthe resistance VRR is shunted out energizing the transfer relays TRAN",TRAN TRAN and TRAN", through a circuit traced as follows :from apositive termin al of battery BT through Wire 197, front contact-205 ofrelay VH wires 206 and 207, automatic cut-out A", wire 208, back contactof relay RE, wire 76', to the contact73 of 1 relayOPR, tothe transferwire 201' asheretofore explained. The relay VH is made to have a slowreleasing period so that the shunting of resistance VRR is accomplishedbefore the. shunt for resistance VR-R is opened. In this manner,additional voltage is applied, as additional transfer relays are placedin the series transfer circuit.

The second cycle of operation is the same the first cycle, except theenergization of the cycle checkingrelay 0K which takes place immediatelyupon the energization of the relay TRAN" for selecting the first waystation. During the second cycle the relay IN" is (ls-energized, so thata circuit is completed for energizing the relay CK as soon as the relayTRAN" has become energized. This circuit for energizing relay 0K istraced as follows :positive terminal of indicated source having suita lepotential, through relay CK", wire 211, back contact 16% of relay IN",wires 167, 165, 215 and 86, positive contact 87 of relay TRAN" to thecommon wire 200. The energization of relay CK",re-rot1tes the stickcircuit of the relay CR, which is traced as follows :from the positiveterminal of indicated source having suitable potential, through thelower winding of relay CR, front contact 50 of relay CR, wire 51, frontcontact 52 of relay CK", wires 168, 165, and 86, positive contact 87 ofrelay TRAN", to the common wire 200.

lit is now easily understood that, as soon as the relay ST" isenergized, energizing the relay RE, and in turn energizing the relayTRAN" with negative potential, the stick circuit for the relay GR isopened at the contact 87 of relay TRAN". lVith the de-energization ofrelay OR, the relay CK is de-energized and the stick circuit for therelays N and P is opened. Also, the energizing circuit for the relay REis maintained, thus, holding the system in the at rest or normal cond1-tion, as heretofore described.

Transmission of control impuZses.-Now let us assume that, the trainwhich OS-ed at the signal SW has now proceeded to the West end of tracksection TK and is ready to accept either signal SlV or SW. Thedispatcher, desiring to route this train upon the passing siding PS,must reverse the track switch TS and clear the signal SW which he may doby moving the levers SML and SL to left hand positions. However, forconvenience in describing the operation of the system in response to themovement of a control lever, the various functions and operations of thesystem will be described first for the lever SML moved to a left handposition.

The lever SML is moved to a left hand position, during the movement ofwhich, the contact 12, mechanically connected to lever SMIF, completes amomentary circuit for energizing the relay G This momentarily madecircuit-, which is completed when any control lever for the second waystation is moved to new position, has two functions, namely, first toregister that a control lever for that particular way station has beenmoved to a new position, which is accomplished by the energization of agroup selecting relay, such as relay G second, to initiate the system,which is accomplished by having make-before-break contacts on the groupselecting relay controlling circuits in such a manner, that, when saidgroup selecting relay is energized, that these make-before-breakcontacts momentarily complete a circuit for energizing the initiatingrelay 1N and the control relay OR.

With the initiating relay 1N and the control relay OR, both energized,the system operates to transfer the dispatchers control from one waystation to the next way station in the usual manner, until the waystation is reached to which a control impulse is to be transmitted,which station, is determined by the energization of its group selectingrelay, which in this particular case is relay G After the stationselecting relay ST is energized, a potential would ordinarily be placedon relay P for effecting the transfer of control to the next waystation. However, with relay G energized, this potential does not go torelay P, but is given to the starting relay ST", which causes thestepping impulse group to operate and place alternate positive andnegative impulses upon the stepping line 202, which cause the relays 1 2and 3 in the dispatchers office to operate sequentially and insynchronism with the relays A 13 and O at the second way station. Assoon as these relays have completed their sequential operation, therelay 3 completes a circuit for energizing the stopping relay STP, whichcauses the stepping impulses to immediately cease. At the same time,apotential is placed on either relay CO or relay CO depending upon theposition of contact 7 2 of relay CO, which contact is in a position asdetermined by the polarity of potential then placed upon relay OPE forselecting the way station then under control. The potential is placedupon the relay CO in this particular illustration, due to the contact 72of relay CO being in a negative position, which energizes the contactsof relay CO so that its stick circuit is closed, as well as a circuitfor energizing the relay P. This circuit for energizing the relay P iscontinued, until the next way station has been selected, at which timethe system operates to select further way stations in the normalOS-scanning manner as heretofore described. Instead of-re-routing thepotential, which holds the starting relay ST energized, to effect thenext transfer impulse, it is cut off by the stopping relay STP so thatsaid potential will produce the energization of relay ST during thesecond cycle of operation.

The second cycle of operation is similar to the first, at the end ofwhich the control relay OR is de-energized, which opens the stickcircuit for the group selecting relay G During the dc-energization ofrelay G a momentarily made circuit re-energizes the initiating relayIN". This causes the system to further operate through two completecycles, insuring that all control inclications and OS indications havebeen brought up to date, which is particularly desirable in systemswhere OS indications giving. the positions of controlled mechanisms areused.

More specifically,- the lever SML being moved to a left hand position,results in a momentarily made circuit for energizing the relay G beingtraced as follows :from the positive terminal of indicated source havingsuitable potential, through relay G wires 215 and 216, contact 12, tothe common wire 200. The energization of relay G results in amomentarily'made circuit for en ergizing the relays INand OR, which maybe traced as follows :from positive terminal of indicated source havingsuitable potential, through upperwind of relay CR, wire 33, relay IN",wires 34, 217 and Y218, make before break contact 219, to the commonwire 200. As the momentarily made circuit for energizing the relays INand OR, is completed while the relay G is but partly energized, and alsorelay Or is slightly slow releasing, then the relay CR has time to reachan energized position to close the stick circuit for relay G beingtraced as follows :from' positive terminal of indicated source havingsuitable potential, through relay G wire 223, front contact 220, wires221 and 222, front contact 17 of relay OR, to the common wire 200.

lVith the energization of the initiating relay IN and the control relayOR, the system is initiated as heretofore described, and the systemoperates to select the first way station, automatically picking up theOS indication at that way station, and automatically leaving the firstway station to place control over the second way station. Thus far, theauto matic control of the system is identical with the operationheretofore described. However, as soon as the second way station isselected the OS indication is transmitted to the dispatchers officeindicating that the track section TK is still unoccupied, during whichtime, the energization of relay ST in the dispatchers office hascompleted a circuit for initiating the impulses to be placed upon thestepping wire 202, used to operate the control impulse message channelselecting relays.

In response to the energization of relay ST a circuit is completed forenergizing the relay ST instead of transferring to the third waystation, because the relay G is energized and remains energized throughits stick circuit. This circuit for energizing relay ST is traced asfollows :from positive terminal of indicated source having suitablepotential, through relay ST wire 22?, back contact 223 of relaySTP,wires 229 and 224, front contact 191 of relay Gflwires 193 and 194,front contact 195 of relay 3T wire 185, back contact 63 of relay 8T tothe common wire 200.

The energization of relay ST places potential upon the relay MB inaccordance with the position of relay 'S which is in a position inaccordance with the position of relay S",

' with said relay S in a position in accordance with the last positionto which the relay MR has been operated. The non-mechanical rotation ofthe relays MR, S and S is explained in great detail in pendingapplication'of F. B. Hitchcock et al. Ser. No. 345,667,

filed March 9, 1929. This reference application, also, describes themanner in which the message sent over message channels, may be placedupon the channel during a central period of time. The same principle ofcontrolling theme-ssage circuits may be used in the present inventionbut for the sake of clearness and simplicity has been omitted.

With the contact 230 of relay STin an energized position, and conditionsas assumed, the relay MR places positive potential upon the steppingwire 202 through a circuit traced as follows :from positive terminal ofbattery BT3, throughpositive contact 231 of relay MR, wire 232, relay S,wire 2'33, relay L through the stepping wire 202 to the first waystation, through Wire 234, front contact 235 of relay SS wire 236,through the stepping wire 202 to the second way station, through relay Lwire 237, back contact 238 of relay SS to the common wire 200. It isassumed that the relay S responds to the positive impulse and relay S isenergized with a negative impulse, thus energizing relay MR with anegative impulse, as explained in application Ser. No. 345,667, andobvious from the drawings. Vith contact 231 of relay MR in a negativeposition, a negative impulse is placed upon the stepping wire 202 fromthe battery IBT through the circuit heretofore traced. Thus, each timethat the contact231 of relay MR moves to a positive position, apositiveim aulse is placed upon the stepping wire 202 an moves the relay S to La new position, which in turn moves the relay S to a new position, whichin turn energizes the relay MR to an opposite position. Thisnon-mechanical rotation of the stepping impulse generating groupcontinues so long as n the circuit for the relay MR is completed.

The stepping impulses placed upon the stepping wire 202are repeated bythe line relayL in the dispatchers ofiice, and by line relay L at thefirst way station, when the first way-station is selected for controlimpulses. When the second way station is selected, the line relay Lrepeats these stepping impulses but the line relay L does not operatedue to the fact that it is shunted out through a circuit heretoforetraced. It is thus seen, that whenever a station is selected forreceiving control impulses, the relays S and L operate in series withthe line relay of the particular way station then selected.

The energization of relay S1 selects the control impulse message channelselecting relay bank composed of relays 1 2 and 3 so that they aresequentially operated when the line relay L is operated. Also, when therelay ST is energized the control impulse message channel selectingrelay bank composed of relays 1", 2 and 3 are sel cted so that theyoperate sequentially when the line relay L is operated. Thus, it is seenthat the station selecting relay ST selects the message channel relaybank of way station one, and the station selecting relay bank ST selectsth message channel selecting relay bank for way station two.

As the relay ST is now energized and the contact 239 of relay L" movesto a positive position then a circuit is completed for energizing relay1 being traced as follows from positive terminal of indicated sourcehaving suitable potential, through positive contact 239 of relay L wires248 and 249, back contact 307 of relay 2 wire 306, through relay 1 wire250, back contact 251, wires 252 and 253, back contact 254, wires 255and 256, front contact 61 of relay ST wires 62 and 185, back contact 63,to the common wire 200. With contact 294 of relay 1 in an energizedposition, a stick circuit is closed for said relay 1 being traced asfollows :from positive terminal of indicated source having suitablepotential, through front contact 294, wire 295, relay 1 wire 250, backcontact 251 of relay 2 wires 252 and 253, back contact 254, of relay 3wires 255 and 256, front contact 61 of relay ST, wires 62 and 185, backContact 63 of relay ST, to the common wire 200.

The relay A at the second way station is energized by the movement ofcontact 240 of relay L to a positive position, through a circuit tracedas follows :from positive terminal of indicated source having suitablepotential, through positive contact 240 of relay L wire 310, backcontact 311 of the relay B wires 257 and 297, through relay A wire 259,back contact 260, wires 261 and 262, back contact 263, wires 264, 265and 266, positive contact 267, to the common wire 200. With contact 296of rel av A in an energized position, a stick circuit is closed for saidrelay A being traced as follows :from positive terminal of indicatedsource having suitable potential, through front contact 296 of relay Awire 297, relay A wire 259, back contact 260 of relay B wires 261 and262, back contact 263 of relay C wires 264, 265 and 266, positivecontact 267 of relay TRAN to the common wire 200.

With the energization of relay 1 and A a message channel is set up whichallows negative potential to be placed upon the switch machine relaySlvflR in accordance with the position of the lever SMIF, which at thistime is in a left hand position. This message channel for the switchmachine relay SMR is traced as follows: from nega tive terminal ofindicated source having suit able potential, through lever Si /1Lthrough wire 241, front contact 151 of relay 1 wir 150, back contact149, wire 143, back contact 147, wire 146, front contact 39 of relay53', wire 40, back contact 41, to the message wire 203 to the second waystation, through wire 242, front contact 145. and positive contact 144of relay TRAN wire 143, frontcontact 142 of relay S wire 141, backcontact 14 of relay SS wire 129, back contact 138 of relay C wire 137,back contact 136 of relay 15 wire 135, front contact 134, of relay 14?,wire 243, relay SMRZ to the common wire 200. This negative potentialplaced upon the relay Sil /ll moves its polar contact to a negativeposition, thus controlling the switch machine 8M in such a manner thatthe track switch T8 will be moved to a reverse position which will allowa train to pass onto the passing siding PS.

The movement of contact 231 of relay MB to a negative position, places anegative impulse upon the stepping wire 202 moving the contact 239 ofrelay 0 to a negative position, completing a circuit for energizingrelays 2 and B respectively.

with contact 239 of relay L in negative position in response to anegative impulse placed upon stepping wire 202, and energizing circuitfor relay 2 is completed, being traced as follows :fr0m positiveterminal of indicated source having suitable potential, through negativecontact 239, wire 267 front contact 268 of relay 1 wire 269, thro" lav 2wires and 253, back contact 254, wires 255 and 256, front contact 61 ofrelay ST wires 62 and 185, back contact 63, to the common wire 200.lVith contact 298 of relay 2 in an energized position, stick circuit iscompleted for relay 2 being traced follows :-from positive terminal ofindicated source having suitable potential, through front cont ct 298 ofrelay 2 wire 299, through relay 2 wires 270, and 253, back contact 254,of relay 2 wires 255 and 256, front contact 61 of relay 8T wires 62 and185, back contact 63 of relay ST to the common \vire 200. Theenergization of relay 2 breaks the stick circuit of relay 1 at the backcontact 251 of relay 2 With the contact 240 of relay L in a negativeposition, a circuit is completed for energizing relay B being traced asfollows:-

from positive terminal'of indicated source having suitable potential,through negative contact 240, wire 271, front contact 272, wire 273,through relay B wires 192 and 262, back contact 263, wires 264, 265 and266, positive contact 267 of relay TRAN to the common wire 200.

lVith the contact 300 of the relay B in an energized position a stickcircuit is completed for relay B being traced as follows :from positiveterminal of indicated source having suitable potential, through frontcontact 300, wire 301, relay B wires 192 and 262, back contact 263 ofrelay C wires 264,265 and 266, positive contact 267 of relay TRAN to thecommon wire 200. The energizatioirof relay B breaks the stick circuit ofrelay A at the back contact 260 of relay B The movement of contact 231of relay'MR to a positive position, places a positive impulse upon thestepping wire 202, which is repeated by the line relays L and L which inturn energize relays 3 and C respectively.

With contact 239 of relay L in a positive position in response to anegative impulse placed upon the stepping wire 202, an energizingcircuit for relay 3 is completed being traced as follows :from positiveterminal of indicated source having suitable potential, through positivecontact 239 of relay L", wires 248 and 249, front contact 307 of relay2", wire 308, relay 3 wires 309 and 256, front contact 61 of relay STwires 62 and 185, back contact 63 of relay 8T to the common wire 200.lVith contact 302 of relay 3 in an energized position, a stick circuitis completed for said relay 3 being traced as follows from positiveterminal of indicated source having suitable potential, through frontcontact 302 of relay 3 wire 303, relay 3', wires 309 and 256, frontcontact 61 of relay 5T wires 62 and 185, back contact 63 of relay ST tothe common wire 200. The energization of relay 3 opens the stick circuitof relay 2 at the back contact 254 of relay 3 With the contact 240 ofrelay L in a posi tive position a circuit is completed for energizingrelay C being traced as follows from positive terminal of indicatedsource having suitable potential, through positive contact 240 of relayL wire 310, front contact 311 of relay B wire 312, relay C wires 313 and265 and 266, positive contact 267 of relay TRAN to the common wire 200.With contact 304 of relayC in an energized position, a stick circuit iscompleted of said relay C being traced as follows :-from positiveterminal of indicated source having suitable potential, through frontcontact 304, Wire 305,

relay C wires 313, 265 and 266, positive contact 267 of relay TRAN tothe common wire 200. The energization of relay C opens the stick circuitof B at the back contact 263 of relay 0?- As soon as the relay 3 1s inan energized inc position, a circuit is completed for energizingtherelay STP,,which stops the stepping impulse generating group of relaysMR, S and S", and also at the same time, the relay 3 closes a circuitfor energizing either relay C0 or relay CC in accordance with theposition of contact 72 of relay CC.

The circuit for energizing the relay STP is traced as follows :frompositive terminal of indicated source having suitable potential, throughrelay STP, wires 274, 275 and 276, front contact 254 of relay 3 wires255 and 256, front contact 61 of relay 8T wires 62 and 185, back contact63 of relay ST to the common wire 200, thus the energy which held thecontact 230 of relay ST in an energized position, is broken at thecontact 228 of the relay STP resulting in the discontinuation of thestepping impulses.

At this time the relay OPR is energized with negative potential througha circuit ineluding-the lower coil of relay CC, causing the contact 72of relay CC to be in a negative position, which results in theenergization of relay CO through a circuit traced as follows :frompositive terminal of indicated source having suitable potential, throughback contact 314 of relay (3C wire 315, relay C0 wires 316 and 277,negative contact 72 of relay CC,wires 278-, 275 and 276, front contact2540f relay 3 wires 255' and 256, front contact61. ofrelay ST wires 62and 185, back contact 63, ofrelay ST to the common wire 200.v As soon asthe contact 317 of relay CC reaches. a fully energized position thecontact 72. of. relay CC is shunted out by means of wire" 318, frontcontact 317, wires 319 and 320,.to the wire 278-, thus completing astick circuit for relayCC so long as the relay ST remains energized.Vith the contact 321 of relay (1G in an energized position a circuit iscompleted for energizing the relay P being traced as follows :frompositive terminal of indicated source having. suitable potential,through front contact 53 of relay CR, wires 54 and 55, relay P, wires56, 189 and 322, front contact 321 of relay C0 to the common wire 200.

With the relay P energized, the stick circuit for the relay N is opened,and the energizing circuit for the relay OPR is opened so that thecontact 72 of relay CG and the contact 73-. of relay OPR assume neutralpositions, until, the relay N becomes fully deenergized, at which time apositive impulse will be placed. upon the relay OPR through circuitsheretofore described. Thus the next way station in successionwill beselected and the system Will proceed under the normal OS-scanningoperation.

In this particular embodiment of the pres ent invention, the next waystationin succes- S1011 is the third and last way station, hence theenergization of relay ST results in the r deenergization of the relay STwhich opens the circuits for relays C0 3 and ST]? and closes the circuitfor the reset relay RE. The system will now operate through the secondcycle as heretofore described in a similar manner to the first cycle, atthe end of which the control relay GR is d e-energized which opens thestick circuit for the group selecting relay G The deenergization of therelay G completes a momentarily made-circuit for reenergizing the relayIN", which results in the further operation of the system through twocomplete cycles, during which only OS indications are transmitted,unless some control lever has been moved in the meantime.

Let us now assume, that the system is again at rest and the dispatchermoves the lever SL to a left hand position, as a result of which thesystem will be stepped along to such points in the cycles of sequentialoperation that control impulse message channels will be set up forcontrolling the relays DR and SR The message channel for relay DB istraced as follows :from negative terminal of indicated source havingsuitable potential, through lever SL wire 244, front contact 149 ofrelay 2 wire 148', back contact 147 of relay 3 wire 146, front contact39 of relay ST wire 40, back contact 41 of relay ST, to the message wire203 to the second way station through wire 242, front contact 145 andpositive contact 144 of relay TRAN wire 143, front contact 142 of relayS wire 141, back contact 140 of relay SS wire 139, back contact 138 ofrelay C wire 137, front contact 136 of relay B wire 245, relay DR to thecommon wire 200.

The message channel for the relay SR is traced as follows :from thepositive potential terminal of indicated source having suitablepotential, through positive contact 13, wire 246, front contact 147 ofrelay 3 wire 146, front contact 39 of relay ST wire 40, back contact 41of relay 8T to the message wire 203 to the second way station, throughwire 242, front contact 145 and positive contact 144 of relay TRAN wire143, front contact 142 of relay S wire 141, back contact 140 of rela SSwire 139, front contact 138 of relay wire 247, relay SR to the commonwire 200.

The energization of relay DB with negative potential effects themovement of its polar contact to a negative position andthe placing ofpositive terminal on relay SR effects the movement of. its polar contactto a positive position, resulting in the clearing of signal SW so thatthe train may pass onto track section TK and over the passing siding PS.

If the synchronous selecting dispatching system as herein describedcomes to rest before the train enters track section TK then tiate thesystem and cause it to operate through two cycles of operation fortransmitting the OS indication to the dispatchers oflice. Thetransmission of this OS indication is accomplished through the systemherein described over a message channel heretofore described, placingnegative potential upon the relay S so that its polar contact assumes apositive position illuminating the indicator lamp l announcing to thedispatcher that the train has passed onto track section TK Immediatelyupon the exit of the rear end of the train from track section TK thefact will be transmitted to the dispatcher by the placing of negativepotential upon the relay 08 moving polar contact to a negative positionand extinguishing the illumination of indicator lamp Also, with thetrain completely on the passing siding, as it has cleared the followingsection of the passing siding, the fact will be transmitted to thedispatcher by energizing the relay USS with negative potential over amessage channel heretofore described, resulting in the extinguishing ofthe illumination of indicator lamp 1 It is of course understood that thesyn chronous selector dispatching system operates in accordance with thepreceding description, thus eliminating the necessity for furtherstating when the system is initiating and when it stops, assuming thatthe message channels are set up and that indications are transmitted inaccordance therewith.

The dispatcher, desiring to route this train back onto the main trackmust reverse the track switch TS and clear the signal SW which may beaccomplished by moving the levers SML and SL to left hand positions.

The messagechannel for the control of relay ShiiR is traced as follows:from negative terminal of indicated source having suitable potential,through lever SML in a left hand position, wire 279, front contact 115of relay 1 wire 114, back contact 113 of relay 2 wire 112, back contact111 of relay 3 wire 110, front contact 37 of relay ST", wire 38, backcontact 39 of relay 8T wire 40, back contact 41 of relay 8T tothe'message wire 203 to the first way station, through wire 280, frontcontact 109 and positive contact 108 of relay Til-APP, wire 107, frontcontact 106 of relay S wire 105, back contact 104, wire 103. backcontact 102 of relay C wire 101, back contact of relay B wire 99, frontcontact 98 of relay A wire 281, relay 8MP to the common wire 200. Thus,the polar contact of relay Sllillt is moved to a negative positionresulting in the movement of track switch TS to reverse positionallowing the passage of the train onto the track section TK and onto themain track as soon as the signal SW shows a proceed indication.

The message channel for the relay D151 is traced as follows :-fromnegative terminal of indicated source having suitable potential,

its

through lever SL in a negative position, through wire 282, front contact113 of relay 2 wire 112, back contact 111, of relay 3 wire 110, frontcontact 37 of relay ST, wire 38, back contact 39 of relay ST wire 40,back contact 41 of relay ST to the message wire 203 to the first waystation, through wire 280, front contact 109, and positive contact 108of relay TRAN wire 107, front contact 106 of relay S wire 105, backcontact 104 of relay SS wire 103, back contact 102 of relay G wire 101,front contact 100 of relay B wire 283, relay DB to the common wire 200.

The message channel for the relay SR is traced as follows :from positiveterminal of indicated source having suitable potential, through positivecontact 10, wire 323, front contact 111 of relay 3 wire 110, frontcontact 37 of relay S'l, wire 38, back contact 39 of relay ST wire 40,back contact 41 of relay ST to the message wire 203 to the first waystation, through wire 280, front contact 109, and positive contact 108of relay TRAN wire 10?, front contact 106 of relay 8, wire 105, backcontact 104 of relay SS wire 103, front contact 102 of relay C wire 324,relay SR to the common wire 200.

With negative potential upon the relay DB its polar contact is moved toa negative position, and with positive potential upon the relay S11 itspolar contact is moved to a positive position, the combination of which,clears the signal SW allowing the train to pass onto the main track. Thepassage of the train over the track section FS and TK results in an OSindication being transmitted to the dispatcher, which is accomplished bya positive potential being placed upon the relay @13 moving its polarcontact to a positive position resulting in the illumination ofindicator lamp 1 As soon as the train is entirely on the track sectionTK the indicator lamp 1 becomes tin-illuminated due to a negativepotential being placed upon the relay 08 The dispatcher may now returnthe control levers to their normal positions, or leave them in theirpresent positions, allowing following trains to be routed over the sametrack, either of which may be done at the option of the dispatcher.

It will be stated here, that if the dispatcher moves one or more controllevers at one time,

then the system operates through two complete cycles for transmittingthe control impulses, and through two complete cycles for clearing upall GS indications. Also, if one control lever is moved to a newposition and then another is moved to a new position some time beforethe system comes to the end of the second cycle for transmitting controlimpulses, then the system is insured of at least one complete cycle ofoperation after the movement of the said second lever. The same is true,should the second lever be thrown some time during the two cycles ofoperation for clearing the OS indications, or in other words during thethird and fourth cycles.

Emergency transfer c0ntr0'Z.Let us assume, that the third way stationbecomes inoperable, due to the fact, that the transfer line wire 201between the second and third stations becomes severed, or opencircuited. Then, after the selection of the second way station, thethird way station cannot be selected because of open circuit, thereforethe transfer relay TRAP will not be energized. However, as the contact77 of relay TRAN" has been assuming a positive position for the transferfrom previous way stations and the contact '78 of relay TRAN" remainsde-energized, then the indicator lamp 1 1 ill remain continuouslyilluminated as is obvious from the drawing showing Fig. 1B. Thecontinuous illumination of said indicator lamp 1 will make the operatoraware of this fact and he will then cause the system to operateautomatically for the first two way stations only, by moving the switchTTS from its present normal position to the dotted line position a. Thesystem will now operate as formerly describedwith the exception of theelimination of the third way station.

In practice there would probably be more than three way stations, on theassumption of which, let us consider the eifect of a short circuit fromthetransfer wire 201 to the common wire 200, somewhere between thesecond and third way stations. When the second way-station is selected,the additional voltage is applied for selecting the third way station,so that when the third way station is selected and the additionalvoltage for selecting the fourth way station is applied, there are twounits of additional voltage applied to the transfer wire. By way ofillustration, assuming that the additional units of voltage applied forthe selection of each succeeding way station are equal, and that theautomatic cut-out A opens the circuit when one and one-half units ofadditional voltage are applied, then upon the selection of the fourthway station, the cut-out A opens the circuit, (ls-energizing the relayTRAN" and causing the indicator lamp 1 to be illuminated. The operatorknowing that the system is arranged to stop on the selection of the waystation beyond that one which is made inoperable by the short circuit,then turns the switch TTS to such a position that the system resets onthe way station at which the short circuit trouble occurs thus givingthe operator automatic control over the part of his system up to thetrouble.

lVher-e the additional units of voltages are not equal then the cut-outA could be set to open the circuit upon some predetermined voltagegreater than the largest unit added.

Then b closirn the automatic cut-out A Summary Some of the basicprinciples will now be set forth, which have not been clearly broughtout by explanation of the operation of the system.

It is highly desirable that all message channels be synchronized at theend of each cycle, which is an inherent characteristic of the presentinvention. By reference to Fig. 10, it is seen that the last operatedcontrol impulse message channel selecting relay C is held energized,until the system is reset or restored to the normal at rest condition,at which timeits stick circuit is opened at the positive contact ofrelay TRAN With this arrangement of circuits, it is seen, that, shouldthe contact 285 of relay SS fail and the line relay L operatesimultaneously with line relay L at the second way station, the relaysA, B and C could not be operated because of relay C being held energizedthrough a stick circuit. Also, the message channel circuit is open, dueto the contact 104 of relay SS being in an energized position. Again,failure in shunting the line succeeding the way-station under control,does no harm, as the polar contacts of the transfer relay are innegative positions, leaving the energizing circuit for the controlindication message channel selecting relays open. Thus, a completeisolation of message channels is accomplished.

It is also noted, that synchronization of station selection isaccomplished at the end of each cycle by the application of a negativeimpulse, regardless of whether some extraneous influence has caused thetransfer control to be ahead or behind the station selecting relays ST,ST and ST in the dispatchers office. If the transfer line 201 issectionalized, the negative impulse on the f rst way station results inthe energization of relay SS causing the transfer line 201 to be madecontinuous to the second way station, which in turn results in theenergization of relay SS making the transfer line continuous to thethird way station and so forth to the end of the line. If the controlover the way station is ahead of the station selecting relays ST, ST and8T then when the end of the system is reached, nothing can happen untilthe apparatus in the dispatchers ofiice catches up, at which time thenegative impulse resets the system for the normal at rest period.

It is also noted, that there are no contacts in the transfer linecircuit, and that all transferring functions are made continuously

